[MermaidMassacre]

Low chance. But if you are on his lap and his precum does absorb through both articles of clothing. Then come in contact with the outside of your vaginal area. You could get pregnant. Not very likely though. Sitting on his lap when you are both naked, is just as unlikely as the first one. Except there is a little more chance. It's mostly just if he precums.

Hahaha @ condomwear. That would work. =P

For the condom thing. If he's not precumming then it should not matter. Just before you come in contact with each other and he is erected. I wouldn't say there is a correct time to put one on. Just do it before you come in contact (penis to vagina).

And if it makes you feel better, you could get one of those day after pills, or pregnancy kits. Whatever you like. =)

Be safe! =P